On July 26, the research journal Science published results from a study done by scientists at the RIKEN-MIT Center for Neural Circuit Genetics that demonstrate how false memories can be created in mice.
The research team was able to implant the brains of genetically engineered mice with optical fibers that can deliver pulses of light into their brains. Using this technique, known as optogenetics, the researchers were able to alter the response of individual neurons. The researchers were ultimately able to make the mice incorrectly associate a benign environment with a previous unpleasant experience from different surroundings.
“If you want to grab a specific memory you have to get down into the cell level,” says Dr. Xu Liu of the Massachusetts Institute of Technology and one of the lead authors of the study in an interview with BBC. “Every time we think we remember something, we could also be making changes to that memory – sometimes we realize, sometimes we don’t. Our memory changes every single time it’s being recorded. That’s why we can incorporate new information into old memories and this is how a false memory can form without us realizing it.”
The brain of a mouse is simpler than a human brain, but the structure is similar enough to provide insights into the functionality of the human brain.
“Humans are highly imaginative animals,” explains Susumu Tonegawa of RIKEN-MIT and a supporting author of the study. “Just like our mice, an aversive or appetitive event could be associated with a past experience one may happen to have in mind at that moment, hence a false memory is formed.”
Some scientists are already thinking of practical applications of the research. Neil Burgess from University College London believes this type of knowledge “may help scientists to understand how to remove or reduce the fearful associations experienced by people with conditions like post traumatic stress disorder,” while Mark Mayford of the Scripps Research Institute in San Diego, Calif., sees potential for “treating diseases of thought such as schizophrenia,” saying, “[W]ork like this could one day further help us to understand the structure of our thoughts and the cells involved. Then one can begin to look at those brain circuits, see how they change, and hopefully find the areas or mechanisms that change with learning. You cannot approach schizophrenia unless you know how a perception is put together.” More sinister applications could also be possible, such as altering the memories of people who are witnesses to crimes so that they cannot give credible testimony in court. But such concerns are many years away, as much more work must be done before such techniques can be used on humans.